1. Technical Field
The embodiments herein generally relate to wireless communications, and, more particularly, to mobile television (TV) technologies.
2. Description of the Related Art
The field of wireless communications, and specifically mobile TV, is plagued with numerous standards that are supported in different parts of the world. This problem led to the requirement of having multi-mode mobile TV devices capable of supporting multiple standards. This is problematic due to the wide variation in specifications of each standard, especially data bandwidth. For high bandwidth standards, a direct conversion front-end receiver architecture is desired for several reasons. First, after mixing down the radio frequency (RF) signal, the baseband operates at the minimum operating frequency (minimizing bandwidth). Second, image rejection is completely eliminated, since there is no intermediate frequency (IF). For low data bandwidth standards, a low-IF heterodyne architecture is desired. A low-IF heterodyne architecture avoids low-frequency flicker noise produced by baseband analog circuitry by shifting the data signal to a frequency slightly away from DC.
One method to realize a multi-standard tuner is to use multiple receiver paths for each standard. While this method is relatively straightforward, it tends to suffer from a number of drawbacks including requiring a large chip/die-area, which translates to lower yield and higher cost; and a larger die area also generally requires larger packages and hence a higher packaging cost as well as a larger printed circuit board (PCB) area. Accordingly, for multi-standard communication systems, there is a strong need for one receiver architecture that can accommodate both narrow bandwidth and high bandwidth standards.